1. Technical Field of the Invention
This invention relates to hydroxy-terminated polyureas and to a method for their preparation. More particularly, this invention relates to hydroxy-terminated polyureas prepared by reacting an organic diisocyanate with a secondary monoalkylamine derivative of a polyoxyethylene glycol, about 2 moles of the monoalkyl amine derivative being used per mole of organic diisocyanate. This invention also relates to hydroxy-terminated polyurea derivatives of secondary monoalkylamines and prepolymers of organic diisocyanates with polyoxyalkylene polyols. The resultant products are useful in the preparation of polyurea-polyesters and are also useful as polyols for reaction with organic polyisocyanates to prepare polyurethanes.
2. Prior Art
Speranza U.S. Pat. No. 3,364,239 is directed to secondary amino polyalkoxy monoalkanols which are prepared by reacting a primary amino polyalkoxy alkanol with a higher carbonyl compound such as methylethyl ketone, butyraldehyde, etc., to form a Schiff base reaction product which is thereafter hydrogenated in the presence of a hydrogenation catalyst at an elevated temperature and pressure to provide the secondary amino polyalkoxy monoalkanol.
Moss U.S. Pat. No. 3,847,992 discloses a process for partially aminating a polyoxyalkylene polyol by bringing the polyol into contact with a hydrogenation catalyst in the presence of hydrogen and ammonia and a suitable hydrogenation/dehydrogenation catalyst at an elevated temperature and pressure.
Renken et al. U.S. Pat. No. 4,618,717 discloses a process for the conversion of an oxyethylene glycol monoalkyl ether to the corresponding primary amine by reaction with ammonia in the presence of a nickel, copper, chromium-containing catalyst.
Copending U.S. patent application Ser. No. 07/465,660, filed Jan. 16, 1990 entitled "Novel Bis-Hydroxy Diamides and Methods Therefor" discloses a process wherein a polyoxyethylene glycol monoamine is reacted with a dicarboxylic acid in the ratio of about 2 moles of the polyoxyethylene glycol monoamine per mole of dicarboxylic acid. The resultant products have the formula: ##STR2##
Speranza and Lin U.S. Pat. No. 4,927,912, issued May 22, 1990 and entitled "Secondary Isopropyl Amines Derived from Oxyalkylene Diamines and Triamines", discloses a method wherein secondary isopropyl amines are prepared by reacting an oxyethylene and/or an oxypropylene primary diamine or triamine with acetone in the presence of a hydrogenation catalyst and hydrogen.
Copending Speranza and Lin U.S. patent application Ser. No. 07/322,021, filed Mar. 13, 1989, and entitled "Secondary Alkyl Amine Derivatives of Ethylene Diamine" is directed to a method for the preparation of secondary alkyl amine derivatives of ethylene diamine by a continuous process wherein the ethylene diamine is reacted with a methyl alkyl ketone in the presence of a bed of pelleted hydrogenation catalysts and hydrogen.
It is known to prepare substituted ureas by reacting isocyanates with amines. It is also known that isocyanates will react with alcohols to provide urethanes. The reactions described in our invention are very selective. That is, the reaction of the isocyanate takes place exclusively with the hindered amine rather than at the hydroxyl group.